Polyalkene substituted carboxylic acids are widely known and used as additives in the preparation of lubricating oils.
Illustrations of such materials are shown in numerous patents.
U.S. Pat. No. 3,215,707 discloses the reaction of chlorine with a mixture of polyolefins having molecular weights up to about 50,000 and maleic anhydride.
U.S. Pat. No. 3,927,041 discloses the reaction of 300 to 3,000 molecular weight polybutene with a dicarboxylic acid or anhydride to form materials which can be used per se, or as esters, amides, imides, amidines, or the like in petroleum products.
U.S. Pat. No. 4,062,786 provides an example (No. 13) of polyisobutylene succinic anhydride having a molecular weight of about 1300, a saponification number of about 100, and about 1.25 succinic anhydride units per polyisobutylene unit.
U.S. Pat. No. 4,123,373 shows a similar material having a molecular weight of about 1400, a saponification number of 80, and about 1.07 succinic anhydride units per polyisobutylene unit.
U.S. Pat. No. 4,234,435 also shows polyalkene substituted dicarboxylic acids derived from polyalkenes having an average molecular weight at 1,300 to 5,000.
Polyalkenyl succinic anhydrides have also been reacted with polyamines to form materials suitable for use as dispersants in lubricating oils.
U.S. Pat. Nos. 4,113,639 and 4,116,876 provide an example of an alkenyl succinic anhydride with a saponification number of 103, about 1.3 succinic anhydride units per hydrocarbon molecule, and in which the molecular weight of the alkenyl unit is about 1,300. The material is then reacted with a polyamine and boric acid U.S. Pat. No. 4,113,639 or with an amino alcohol and boric acid U.S. Pat. No. 4,116,876.
U.S. Pat. No. 4,548,724 teaches of a lubricating oil additive of the reaction product of a polycarboxylic acid, e.g., 1,3,6-hexane tricarboxylic acid, with a polyisobutylene succinimide of a polyamine.
U.S. Pat. No. 4,579,675 relates to the reaction products of polyalkylene succinimides (derived from polyethylene-polyamines) and 1,3-dicarbonyl compounds. However, the reaction temperatures are such that the products are materials known as N-substituted enaminones. Therefore, polyisobutenyl succinimide, derived from polyisobutenyl succinic anhydride and diethylene triamine, was reacted with ethyl acetoacetate at 110.degree. C. to form the corresponding N-substituted enaminone. The enaminone reaction products are said to have detergent/dispersant properties when included in a lubricating oil composition.
No known disclosure suggests either the products disclosed herein or the use of these products as additives in the preparation of lubricating oils and concentrates which are stable to phase separation.